Central Bureau for Astronomical Telegrams
IAUC 4667: 1987A; V471 Tau
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Circular No. 4667
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505
MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
S. M. Matz, National Research Council/Naval Research Lab
(NRC/NRL) and Northwestern University; G. H. Share, NRL; and E. L.
Chupp, University of New Hampshire (UNH), on behalf of their
collaborators at NRL, UNH, and the Max Planck Institute, Garching,
report: "The Gamma-Ray Spectrometer on NASA's Solar Maximum Mission
satellite continues to monitor 56Co line emission from the supernova.
During the most recent observation intervals, the preliminary
average fluxes (units 10E-4 photon cm-2 s-1) for the 847- and 1238-keV
lines are, respectively: June 15-July 20, 5.1 +/- 3.4, 3.8 +/-
2.9; Aug. 7-Sept. 10, 2.0 +/- 3.4, 3.7 +/- 3.0. Quoted
errors are 1 sigma and represent a combination of statistical and
systematic uncertainties."
V471 TAURI
E. M. Sion, Villanova University; F. C. Bruhweiler, Catholic
University of America; K. Carpenter, Goddard Space Flight Center,
NASA; and D. J. Mullan, Bartol Research Institute, report:
"IUE High-Resolution SWP and LWP spectra of the Hyades member
V471 Tau (an eclipsing-spectroscopic, pre-cataclysmic, close binary
having spectral types K2 V + DA2) reveal very-high-velocity, cool,
expanding gas (Fe II, Si II, C II, Mg II, O I), along the line-of-sight
to the binary system, with an expansion velocity of -1200 km/s.
There is no variation of the co-added absorption feature with orbital
phase and its equivalent width is 0.035 nm, with FWHM = 30 km/s. The
absorption appears in seven lines of the Fe II uv1 multiplet (258.5-261.7
nm), co-added in velocity space for each of the 11 LWP images around
the orbit, in co-added LWP velocity plots of Mg II, Mn II, and Cr II,
as well as in SWP plots of C II (133.5 nm), Si II (126.0 nm), and O I
(130.2 nm), co-added in velocity space. This feature very likely has
an origin distinct from the persistent lower velocity (-500, -260
km/s) absorption components of the K2 V stellar wind discovered by
Mullan et al. (1988, ESA SP-281, p. 378; Ap.J. Letters, submitted) and
from the narrow co-added feature of C II, Si II, and O I, at -590 km/s
discovered by Bruhweiler and Sion (1986, Ap.J. 202, L45). The large
expansion velocity suggests the possibility of its association with an
ancient nova outburst. Further observations in other wavelength regions,
including deep CCD imaging and direct photography, are strongly urged."
1988 October 24 (4667) Daniel W. E. Green
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